# NTSB ANC81DA040: Enstrom F280C, N51732, Aniak, AK, April 9, 1981

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: April 9, 1981
- Place: Aniak, AK · ANIAK, AK
- Location: 61.5799° N, 159.5476° W: Placed by OpenAirDocs: center of Aniak, AK, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=61.5799&lon=-159.5476&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report April 28, 1981
- Report: Brief approved by the director
- NTSB case key (mKey): 127054
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC81DA040
- Page: https://openairdocs.org/ntsb/ANC81DA040

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-0819   81/4/9    ANIAK,AK            ENSTROM F280C       CR-  0  0  1  NONCOMMERCIAL             COMMERCIAL, AGE 33, 1600
        TIME - 1530                    N51732              PX-  0  0  1  CORP/EXEC                 TOTAL HOURS, 600 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            INSTRUMENT RATED.
        NAME OF AIRPORT - ANIAK
        DEPARTURE POINT             INTENDED DESTINATION
          ANIAK,AK                    FIELD SITE
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            TAKEOFF: INITIAL CLIMB
           COLLISION WITH GROUND/WATER: CONTROLLED                  LANDING: POWER-OFF AUTOROTATIVE LANDING
        PROBABLE CAUSE(S)
           PILOT IN COMMAND - SPONTANEOUS-IMPROPER ACTION
        FACTOR(S)
           WEATHER - RAIN
           WEATHER - FOG
           WEATHER - ICING CONDITIONS-INCLUDES SLEET,FREEZING RAIN,ETC.
           TERRAIN - HIGH VEGETATION
           MISCELLANEOUS ACTS,CONDITIONS - AIRFRAME ICE
           MISCELLANEOUS ACTS,CONDITIONS - VIBRATION,EXCESSIVE
        PARTIAL POWER LOSS - PARTIAL LOSS OF POWER - 1 ENGINE
        WEATHER BRIEFING - NO RECORD OF BRIEFING RECEIVED
        WEATHER FORECAST - UNKNOWN/NOT REPORTED
        EMERGENCY CIRCUMSTANCES - FORCED LANDING ON AIRPORT/SEAPLANE BASE/HELIPT.
        SKY CONDITION                                            CEILING AT ACCIDENT SITE
          OVERCAST                                                  1200
        VISIBILITY AT ACCIDENT SITE                              PRECIPITATION AT ACCIDENT SITE
          5 OR OVER(UNLIMITED)                                     RAIN
        OBSTRUCTIONS TO VISION AT ACCIDENT SITE                  TEMPERATURE-F
          FOG                                                       32
        TYPE OF WEATHER CONDITIONS                               TYPE OF FLIGHT PLAN
          VFR                                                      NONE
        REMARKS- IGN SW INADVERTENTLY TURNED OFF WHEN PLT ATMPTD RELEASE SLING LOAD BECAUSE OF SEVERE VIBRATION.
```

## Aircraft

- Registration: N51732 (not matched to a registry record)
- Reported make and model: ENSTROM F280C
- Category: Helicopter
- Engines: reciprocating
- Damage: Substantial damage
- Airport: Aniak

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19810409016829A](https://openairdocs.org/incident/19810409016829A), Apr 9, 1981: Enstrm 280C, Aniak, AK, Substantial damage. Developed excessive rotor vibration on takeoff. Autorotated into brush. Possible ground resonance from sling load.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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